Iraqi army soldiers stage on the outskirts of Hawija, 150 miles north of Baghdad, Iraq.

BAGHDAD — Iraqi soldiers backed by tanks retook control of a Sunni town north of Baghdad on Friday after gunmen withdrew without a fight, although violence erupted at three Sunni mosques and clerics called for the formation of a tribal army to protect Sunni cities.

The Sunni gunmen had seized Suleiman Beg on Thursday after a firefight with security forces, one in a string of similar incidents that have killed more than 150 people in clashes in Sunni Muslim towns in western and northern Iraq during the past four days. The fighting has raised concerns about a rising number of sectarian clashes in Iraq where Sunnis are alleging mistreatment by the government dominated by the Shiite majority.

Police and military officials said army units entered the town after negotiations with local tribal leaders.

The recent unrest in the country followed a deadly security crackdown on a Sunni protest in the northern town of Hawija four days ago.

In Iraq’s predominantly Sunni provinces, anti-government rallies continued as preachers at protest sites called for the formation of tribal army that would protect Sunni areas from attacks by government forces.

In Samarra, Sunni cleric Najih al-Mizan lashed out at what he said were “the policies of tyranny and repression” adopted by Iraqi Prime Minister Nouri al-Maliki. He said al-Maliki’s resignation was the only solution to save the country from the current crisis.

“We call upon our tribes to form an army that can protect us from a government that does not hesitate to kill its people,” said al-Mizan.

In Fallujah, Sunni cleric Ali al-Basra repeated the call to form a tribal army to protect Sunni cities. Several protesters held aloft al-Qaida flags during the rally.

The new calls for Sunnis to take up arms could further raise the tension between the government and the Sunni minority. Al-Maliki appeared on national television on Thursday to appeal for calm.

But on Friday, a bomb blast hit Sunni worshippers as they were leaving a mosque in western Baghdad after the end of Friday prayers, killing five worshippers and wounding 22 others. Minutes later, a Sunni was killed and six others were wounded when a bomb struck Sunnis near a mosque in the Rashidiyah area, 20 kilometers north of the capital. Also, a bomb exploded near a third Sunni mosque in northeastern Baghdad, killing two people.

There was no claim of responsibility for the attacks against Sunni mosques, which have now happened for two Fridays in a row. Last Friday, a pair of bombs struck outside a Sunni mosque north of Baghdad, killing at least 11 people.

Also on Friday, police said a bomb exploded shortly after sunset near a small restaurant in Baghdad’s Shiite neighborhood of Sadr city, killing four people and wounding 20 others. Later on, police said three people were killed and 17 others wounded after a car bomb went off in a commercial street in southern Baghdad.

Al-Qaida’s Iraqi branch, known as the Islamic State of Iraq, frequently carries out attacks against civilian targets such as mosques, markets and restaurants. The terrorist group mainly target Shiites, but it has also struck Sunni targets in an attempt to re-ignite the sectarian strife that pushed the country to the brink of civil war in the years following the 2003 U.S. led-invasion.

Medics in nearby hospitals confirmed the death toll. All officials spoke on condition of anonymity because they are not authorized to talk to media.